UsesTerbinafine (Lamisil) is a second-generation allylamine that is related to naftifine; however, it is 10 to 100 times more potent in vitro. It is fungicidal, whereas griseofulvin, ketoconazole, itraconazole, and other azole derivatives are all fungistatic. Because it is fungicidal, duration of therapy is shorter, and relapse rates are less than with other oral or topical therapies. Terbinafine acts by inhibiting squalene epoxidase and thereby decreasing synthesis of ergosterol, an essential component of fungal cell membranes. It is highly lipophilic and concentrates in the stratum corneum, sebum, and hair follicles. Slightly better cure rates are attained with b.i.d. than with daily dosing.

DefinitionChEBI: A tertiary amine that is N-methyl-1-naphthalenemethylamine in which the amino hydrogen is replaced by a 3-(tertbutylethynyl)allyl group. An antifungal agent administered orally (generally as the hydrochloride salt) for the t
eatment of skin and nail infections.

Pharmaceutical ApplicationsA synthetic allylamine available as the hydrochloride for oral
and topical administration.

PharmacokineticsOral absorption: 70–80%
Cmax 250 mg oral: c. 1 mg/L after 2 h
Plasma half-life: c. 17 h
Volume of distribution: 1000 L
Plasma protein binding: >99%
Blood concentrations increase in proportion to dosage. It is
lipophilic and is rapidly and extensively distributed to body
tissues. It reaches the stratum corneum by diffusion through
the dermis and epidermis, and secretion in sebum. Diffusion
from the nail bed is the major factor in its rapid penetration
of nails. It is metabolized by the liver and the inactive metabolites
are mostly excreted in the urine. The elimination half-life
is prolonged in patients with hepatic or renal impairment.